According to Merriam-Webster Dictionary Online, the meaning of the word "plagiarize" is:
To steal and pass off (the ideas or words of another) as one's one: use (another's production) without crediting the source.
Source:https://www.merriam-webster.com/dictionary/plagiarize
The following videos offer helpful information understand plagiarism and how to avoid it.
How to Paraphrase: Avoid Plagiarism in Research Papers with Paraphrases & Quotations by Dr. David Peak
Quoting, Paraphrasing, and Summarizing -- Oh, My! -- a blog entry from EasyBib